﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Globalization;

namespace _6_Validations
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
            Grid1.DataContext = new DateForm { StartDate=DateTime.Now };
        }
    }

    public class DateForm
    {
        public DateTime StartDate { get; set; }
    }

    public class DateConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter,
                              CultureInfo culture)
        {
            if (value is String)
            {
                DateTime output;
                if (DateTime.TryParse(value.ToString(), out output))
                {
                    return output;
                }
            }

            return value;
        }

        public object ConvertBack(object value, Type targetType, object parameter,
                                  CultureInfo culture)
        {
            if (value is DateTime)
            {
                return ((DateTime)value).ToShortDateString();
            }
            return value;
        }
    }

    public class PastDateRule : ValidationRule
    {
        public override ValidationResult Validate(object value, CultureInfo cultureInfo)
        {
            DateTime date;
            try
            {
                date = DateTime.Parse(value.ToString());
            }
            catch (FormatException)
            {
                return new ValidationResult(false, "Value is not a valid date.");
            }
            if (DateTime.Now.Date < date)
            {
                return new ValidationResult(false, "Please enter a date in the past.");
            }
            else
            {
                return ValidationResult.ValidResult;
            }
        }
    }
}
